Machinery key



Dec. 7, 1943.

R. T. OLSON MACHINERY KEY Filed June 15, 1942 2 Sheets-Sheet l 0 a w w, by 11 mu w gang H W5 Q w 17/ ///%//MM 46 w r A a 1. M

MACHINERY KEY Filed June 15, 1942 2 Sheets-Shed 2 R. T. OLSON 2,336,285

Patented Dec. 7, 1943 UNITEDSTATESV PATENT OFFICE MACHINERY KEY Raymond T. Olson, Stratford, Conn. Application June 15, 1942, Serial No. 447,169

9 Claims. (-1. 85--8.5)

The present invention relates to improvements in machinery keys and relates more particularly to improvements in multiple-part self-locking machinery keys for use in coupling rotary machine elements together such, for instance, as shafts and gears.

One of the' objects of the present invention is to provide a superior multiple-part self-locking machinery key which combines convenience of installation and removal with capacity for holding itself against longitudinal displacement, despite vibrational tendencies of the machinery with which the key may be used.

Another object of the present invention is to provide a superior machinery key of the character referred to which will successfully resist strains tending to cause it to turn about its longitudinal axis in the complemental keyways in the two machinery elements which the key may serve to couple together.

A further object of the'present invention is to provide a superior multiple-part elf-locking machinery key which will effectively lock itself in place without tending to cause eccentricity between the parts which it serves to couple together.

With the above and other objects in view, as will appear to those skilled in the art from the present disclosure, this invention includes all features in the said disclosure which are set fort in the appended claims.

In the accompanying drawings in which certain modes of carrying out the present invention are shown for illustrative purposes:

Fig. 1 is a view in end elevation of a shaft and gear shown as coupled together by a key embodying the present invention;

Fig. 2 is a broken longitudinal sectional view taken on the line 22 of Fig. 1;

' Fig. 3 is a broken longitudinal sectional view taken on the line 3-3 of Fig. 1;

Fig. 4 is a broken transverse sectional view taken on the line 4-4 of Fig. 3;

5 Fig. 5 is a similar view taken on the line 5-5 of Fig. 3;

Fig. 6 is an exploded perspective view of the key-parts;

Fig. 7 is a perspective view showing a preferred mode of installing a key of the present invention in the complemental keyways of a shaft and gear;

Fig. 8 is a similar view but showing a preferred mode of removing the key;

Fig. 9 is a perspective view of an alternative form of key; and

Fig. 10 is a perspective view of still another alternative form of key.

The structure of Figs. 1 to 8 inclusive The particular three-part self-locking machinery key herein chosen for purposes of illustratin the present invention in these figures, comprises complemental laterally-spaced-apart side-plates l0 and H and a central expandingplate I2. Each of the side-plates I!) and I! is preferablyformed of steel and is provided at its outer end with a laterally-extending integral head I3. The central expanding-plate i2 is also preferably formed of steel and is also provided at its outer end with a laterally-projecting head 14 for purposes as will hereinafter appear.

Preferably and as shown, the head M of the expanding-plate or member [2 has a greater length longitudinally of the key-structure than have the heads |3-l3 of the complemental sideplates or members ID and l l. Preferably also, the expanding-plate I 2 has a slightly-greater overall length than the over-all length of the complemental side-plates Ill and Ii. 7

The outer side-face Itor each of the respective side-plates l0 and H extends in substantial parallelis m with the similar side-face of the other of said side-plates, and all of the plates 58, ii and I2 are preferably so proportioned as to provide a joint cross-sectional form which is a substantially equilateral rectangle with the exception that when designed for ordinary keyways, the combined lateral width of the three elements l9, H and i2, when seated in the keyways, will ordinarily have a dimension slightly exceeding the height of the members I9, I! and i2, By way of example, a key which is nominally rated at one inch in cross-sectional form to be accommodated in opposed and aligned keyways of a shaft and gear, for instance, would be so proportioned as to assume a full one-inch circumferential dimension (dimension A of Fig. 4) While its dimension in a direction parallel with the side-faces l5-l5 of the side-plates l0 and II (dimension B of Fig. 4) would be approximately /s4 of an inch scant of one inch.

In the particular embodiment shown, each of the side-plates l0 and II is tapered from its inner to its outer end so that the inner end of each of the said side-plates is thicker than its outer end to thereby provide an inclined inner face l6. On the other hand, the central expanding-member I2 is tapered inwardly from its outer or head end to its inner end to provide the said plate 2 with sloping outer side-faces H which respectively conform in taper or slope to the slope or taper of the inner face '6-.-| 6 of the complemental side-plates l0 and II. It is obvious that, if desired, the direction of tapers just referred to may be reversed though it is preferred that the tapers ofthe members l0, II and i2 or their equivalents be in the direction described for reasons of convenience of use.

The degree of taper of the inner-faces l6-|6 of the side-plates l0 and II is of vital import inasmuch as it must not exceed of an inch per foot of length. Preferably the taper referred to is maintained at substantially '1 inch per foot of length since such a degree of taper has been found to provide maximum resistance to the longitudinal displacement of the plates H), H and i2 when subjected to severe vibration as an incident to their use in machinery.

The preferable practice in installing the three part self-lacking key shown, in the aligned and. opposed keyways of two machinery parts such, for instance, as a shaft 18 and a'gear i9, is tov first back-out the central expanding-plate I 2 with reference to the complemental side-plates l9 and II into substantially the relationship shown in Fig. 7. In this condition, the three plates ill, H and I2 may be conveniently introduced into the keyways with a relatively-free sliding fit. Before the plates I0, I! and [2 are fully inserted into the keyways of the members I8 and 29, it is most convenient to place a stopplate 20 or its equivalent in position to check the inward movement of the side plates Ill and l I in a manner illustrated in Fig. 7. When the parts it, I! and i2 have been moved into the keyways suificiently to engage the respective inner faces of the heads l3 of the side-plates l and H with the outer edge of the stop-plate 2B, the central expanding-plate may be driven in, with a hammer or its equivalent until the desired degree of tightness is achieved. Ordinarily, the expanding-plate l2 would be driven in until the inner face of its head l4 was in engagement with the stop-plate 20, but if a furtherdegree of tightness is required, the stop-plate 20 may be removed and the expanding-plate. l2 driven further in.

'Since the side-faces of the keyways in the shaft 88 and gear l9 are most apt to be relatively rough, it is to be noted that, in tightening the composite key in place, the sliding movement is between the relatively-smooth inner faces ifs-l5 of the side-plates l0 and II and the opposite outer faces |l--|1 of the expanding-plate 52. Under most conditions, the stopplate 20 above referred to is merely useful as .a gauge in definitely positioning the side-platesv ii: and ii before the expanding-plate I32. is, driven home. When the central, expanding..- member E2 is driven home, a uniform lateral expansion occurs throughout the length of the. composite key and not only are the three plates. of the keys retained against longitudinal. dis,. placement with respect, to each other, but the key itself and the shaft l8 and gear I9, or their equivalents, are each held against displacement with respect to each other in a direction lengthwise of the key.

When it is desired, to. remove the key, the stop-plate 2% or its equivalent may be pl'acedas shown in Fig. 8, between the outer face of the gear it and the inner face of the head Mofthe expanding-plate i2 and thereafter the side, plates 59 and H may be driven inwardly by means of a drive-bar 2|, which'latter may be propelled by a hammer or other suitable tool, as indicated in Fig. 8. When the side-plates, it and H have been driven in relatively tothe. central expanding-plate l2, the lateral dimen:- sions of the composite key are thereby reduced,

and the entire three plates W, H andlZ maybe:

jointly withdrawn from the shaft l8 and ear la while in substantially the relationships shown The structure of Fig. 9

In large size keys, instead of providing integral heads such as the heads 13 and [4 before described, I may, if desired, provide each of the three plates Illa, Ila. and [2a of a self-locking key shown in Fig. 9, with heads in the form of machine screws or studs 22. Also if desired and as, shown in Fig. 9, each of the three plates such as the plates lfia, Ila and I2a, may be be provided with a transverse aperture 23 adjacent its outer end. All three plates may be ultimately locked together after their installation by means of a suitable transverse binding-screw such as is indicated by the broken lines 23a and extended jointly through the aligned apertures 23, 23, 23 of the respective plates.

The structure of Fig, 10

As shown in Fig. 10, a key comprising complement'al side-plates Nb. and Nb, as well as central expanding-plates lZb, may have each' of its, said side-plates provided with one of two relatively-small headsv 2424,, respectively lightly welded to the outer end of each of. the said side-plates Nib and H12, so that, once they havev served their purpose, they may be knocked off. and discarded.

The expanding-plate l2bmay be provided in its outer end with a threaded socket 25 into which may be threaded any suitable screw, such as. is indicated by the broken lines. 25a, to act asv a hold-back in lieu. of ahead such as l4 or 22..

The composite key of Fig. 10 is admirably suitedfor use in situations. where it is desired. to have the outer endoflthekeyflush or substantially flush with the outer. ends of the keyways in. which it may be fitted.

The invention may be carried out in other specific ways than thoseherein set forth with.- out departing from the spirit and essential characteristics of the invention, and the present embodiments are, therefore,- to be considered in all respects as illustrative and not restrictive, andall changes coming within the meaning and. equivalency range of the appended claims are intended to be embraced therein- I claim: a

l. A multiple-partv self-locking machinery key, including in combination: two complimental laterally-spaced-apart: side-plates each of substan-- tially-rectangular form-in cross section and having an outer side-face extendingin substantial parallelism with the outer side-face of the other side-plateand each having an inner face sloping longitudinally withrespect' to its outer sideface to a degree ofless- -than%4" per foot of length; and an expanding-plate of substantiallyrectangular form in cross sectionand located between the two said side-plates andhavin'g each of its respective opposite side-faces'conforming in longitudinal slope to and engaging with the inner face of the. adjacent one ofthe two said side-plates. e

2'. A ,multipleepartself-locking machinery key; including .in combination:- two complemental laterally-spaced apart side-plates eachfof sub-; stantially-rectangular form, in cross section and having an outer side-face extending, insubstantial parallel-ismwith the outer side-faceofthe other side-plate and each-having inner face..

sloping longitudinally with. respect to itsouter side-face to a'degree'of lessthan'ug per foot of length, each of the saidside-platesbeing; formed adjacent its -outer end withhold-backimeans' to limit its penetration into a keyway; and an expanding-plate of substantially-rectangular form in cross section and located between the two said side-plates and having each of its respective opposite side-faces conforming in longitudinal slope to and engaging with the inner face of the adjacent one of the two said side-plates, the said expanding-plate also being formed adjacent its outer end with hold-back means.

3. A multiple-part self-locking machinery key, including in combination: two complemental laterally-spaced-apart side-plates each of substantially-rectanuglar form in cross section and having an outer side-face extending in substantial parallelism with the outer side-face of the other side-plate and each having an inner face sloping longitudinally with respect to its outer side-face to a degree of less than per foot of length, each of the said side-plates being formed with a laterally-projecting hold-back head; and an expanding-plate of substantially-rectangular form in cross section and located between the two said side-plates and having each of its respective opposite side-faces conforming in longitudinal slope to and engaging with the inner face of the adjacent one of the two said side-plates, the said expanding-plate being provided with a laterally-projecting hold-back head.

4. A multiple-part self-locking machinery key, including in combination: two complemental laterally-spaced-apart side-plates each of substantially-rectangular form in cross section and having an outer side-face extending in substantial parallelism with theouter side-face of the other side-plate and each having an inner face sloping longitudinally with respect to its outer sideface to a degree of less than per foot of length, each of the said side-plates being provided with a laterally-projecting hold-back stud to limit its penetration into a keyway; and an expanding-plate of substantially-rectangular form in cross section and located between the two said side-plates having each of its respective opposite side-faces conforming in longitudinal slope to and engaging with the inner face of the adjacent one of the two said sideplates, the said expanding-plate being provided with a laterally-projecting hold-back stud.

5. A multiple-part self-locking machinery key, including in combination: two complemental laterally-spaced-apart side-plates each of substantially-rectangular form in cross section and having an outer side-face extending in substantial parallelism with the outer side-face of the other side-plate and each having an inner face sloping longitudinally with respect to its outer side-face to a degree of less than per foot of length; and an expanding-plate of substantially-rectangular form in cross section and located between the two said side-plates and having each of its respective opposite side-faces conforming in longitudinal slope to and engaging with the inner face of the adjacent one of the two said side-plates, the said expanding-plate being formed in its outer end witha threaded socket for the reception of a hold-back screw.

6. A multiple-part self-locking machinery key, including in combination: two complemental laterally-spaced-apart side-plates each of substantially-rectangular form in cross section and having an outer side-face extending in substantial parallelism with the outer side-face of the other side-plate and each having an inner face sloping longitudinally with respect to its outer side-face to a degree of less than /64" per foot of length; and an expanding-plate of substantially-rectangular form in cross section and located between the two said side-plates and having each of its respective opposite side-faces conforming in iongitudinal slope to and engaging with the inner face of the adjacent one of the two said sideplates; each of the two said side-plates and the said expanding-plate being formed with a transverse aperture positioned to align with the apertures in the remaining plate when the key is seated in the keyways of machinery parts. a

7. A multiple-part self-locking machinery key, including in combination: two complemental laterally-spaced-apart side-plates each of substantially-rectangular form in cross section and having an outer face extending in substantial parallelism with the outer side-face of the other sideplate and each having a sloping inner face diverging from its outer side-face progressively from its outer to its inner end to a degree of less than /64" per foot of length; and an expanding-plate of substantially-rectangular form in cross section and thicker at its outer end than at its inner end and located between the two said side-plates and having each of its respective opposite sidefaces conforming in longitudinal slope to and engaging with the inner face of the adjacent one of the two said side-plates.

8. A multiple-part self-locking machinery key, including in combination: two complemental laterally-spaced-apart side-plates each of substantially-rectangular form in cross section and having an outer side-face extending in substantial parallelism with the outer side-face of the other side-plate and each being thicker at its inner end than at its outer end, each of the said sideplates having an inner face sloping longitudinally with respect to its outer side-face to a degree of less than ha" per foot of length, and each of the said side-plates being formed with holdback means to limit its penetration into a keyway; and an expanding-plate of substantiallyrectangular form in cross section and thicker at its outer end than at its inner end and located between the two said side-plates and having each of its respective opposite side-faces conforming in longituidnal slope to and engaging with the inner face of the adjacent one of the two said side-plates.

9. A multiple-part self-locking machinery key, including in combination: two complemental laterally-spaced-apart side-plates each of substantially-rectangular form in cross section and having an outer side-face extending in substantial parallelism with the outer side-face of the other side-plate and each being thicker at its inner end than at its outer end, each of the said sideplates having an inner face sloping longitudinally with respect to its outer side-face to a degree of less than /64" per foot of length, each of the said side-plates being formed with a laterallyprojecting integral hold-back head to limit its penetration into a keyway; and an expandingplate of substantially-rectangular form in cross section and thicker at its outer end than at its inner end and located between the two said sideplates and having each of its respective opposite side-faces conforming in longitudinal slope to and engaging with the inner face of the adjacent one of the two said side-plates.

RAYMOND T. OLSON. 

